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3:00 PM
@BalarkaSen twice as many people think you're a cock?
@Mostafaııııııııııııııııııııııı nice, I've updated the meta post
@0celóñe7 so can you give the name of the books to someone who does not know the books
@JohnRennie haha
@Черенки What he wrote down are the authors of the books. Where they have written several, the phrase in brackets is enough to identify the correct one.
@ACuriousMind are those books a collaboration or is it 1 book per writer?
3:02 PM
single author
1 book per book
I forgot functional analysis though
Pick your poison there
Yosida, Rudin, Conway (functional)
Joseph Smith (The Book of Mormon)
these are books to read so i can grasp qm and gr
well, for GR you need a lot more
at least 3 books on Sobolev spaces
@Mostafaııııııııııııııııııııııı that's a meme book
@0celóñe7 the book by abbott is flatland right?
@Черенки Uh, no, "understanding analysis"
@0celóñe7 Remember that what you call GR is not what the average physicist will call GR ;P
3:06 PM
@ACuriousMind Oh, he just wants average physicist GR?
@Черенки Read Hartle
I don't think it has prerequisites
@0celóñe7 Well, I think that might be the working assumption when someone comes to a physics chat asking to learn GR
@ACuriousMind most of us are mathematicians though
the chat regulars (you, me, @AccidentalFourierTransform, @BalarkaSen) are, at least
If I'm wrong, and you, @Черенки, actually want to learn fully mathematical GR, then please correct me
you are wrong :P
@0celóñe7 Neither me nor AFT are mathematicians, we just have a higher-than-average love of mathematics
3:08 PM
@ACuriousMind yes. I feel obligated to actually mention that I love Shankar's QM, as an introductory text. That photo was merely a joke (please forgive me for that, Shankar)
@Черенки You want to learn mathematical GR?
@ACuriousMind speak for yourself I loath mathematics
@AccidentalFourierTransform you're just in denial
I am not a mathematician. I just don't know anything other than mathematics.
@0celóñe7 yes
3:09 PM
It's controversial that if I even know mathematics.
@BalarkaSen The weird literature that you read falls in the category of math then. XD
oh i meant academically
@Черенки Ah, well then
I can make a list
i take huge proud in knowing a lot of dank memes
@0celóñe7 if you have time
why not
3:11 PM
@Черенки I've been meaning to write this list
It includes books to read and references
God knows I haven't read all of these
books I know what's in all of them and have used them
@0celóñe7 is it a list that is legible to homosapiens?
No, you have to be homo sapiens sapiens
Depends on the type of homo sapien.
emphasis on homo
@Blue i meant the list not the books
3:13 PM
i'd make a goku joke but that'd sound lame
@BalarkaSen Goku? Dragon Ball?
yes. one of the major meme animes in history
Aaaaaaah. I loved Dragon Ball as a child. They stopped streaming it on TV ;-;
I watched upto the Majin Buu episodes iirc
3:17 PM
^ see?
That's Cell
@BalarkaSen Why does everything have to be a "meme"? The word has lost all meaning.
@0celóñe7 can you mention me if you send the list pls
@ACuriousMind Not everything is memable.
3:21 PM
@ACuriousMind oh please
What do you think the word means?
@0celóñe7 will you send the list?
The most hit meme from DBZ is "It's over 9000"
@skullpatrol: My informative post got trashed even before I could reply to you. Oh well. Sometimes I cannot understand why crank advertisements are allowed to stay while objections are not.
Sometimes I cannot understand why 0celo7 is allowed to stay while John Duffield is not.
Don't mention the name. You run the risk of getting banned. :P
3:25 PM
@0celóñe7 Originally it was supposed to mean "cultural analogue to gene". Then it came to mean "funny pictures on the internet with semi-standardized text". Now it seems to mean something akin to "pop culture reference" as far as I can tell, where the pop culture itself partly consists of the pictures.
yeah memes are a meme
how bout dat
@AccidentalFourierTransform To lighten the mood, here's a fun video:
3:32 PM
@ACuriousMind can we please make it a global rule to alert people to YT videos
Authority always wins.
@0celóñe7 I'm not sure what you mean by alerting people
Has over-the-air wireless charging been commercialized yet? I keep seeing/hearing Apple and some other companies claim that they'll be implementing it in their next flagship.
I wonder how they would reduce the flux loss
@blue: presumably you mean beaming the wireless charging over a distance, not just using a wireless charging pad. The latter have been around for years.
3:36 PM
@JohnRennie The former. Yes
Making the latter is quite easy :P
@Blue As far as I'm aware no-one has got it to work in any useful way.
@JohnRennie Yup. Seems so. I've been looking around the net for ways to reduce the flux loss.
Sounds inherently unsafe.
MIT students made some cool progress in 2013-14
3:39 PM
@skullpatrol Hmm, that too
Another problem
@skullpatrol you do wonder what happens if you walk between the wireless power source and the device that's receiving the charge. Would you get charged instead? Wouldn't that be a bit like walking into a running microwave oven? :-)
Yup :-)
I'm sure that happened in one of the original Star Trek episodes and the red shirt involved got vapourised :-)
3:40 PM
@ACuriousMind making a spoiler warning type thing
@JohnRennie I'd wager they use frequencies that are also used for WiFi etc. that do not significantly interact with living matter
You don't like mellencamp? @0celóñe7
@0celóñe7 Oh, you mean not one-boxing the videos?
Not that anyone is interested, but the Star Trek episode where the crewman is vapourised by a wireless transmission beam is The Ultimate Computer.
@JohnRennie I'm surprised it is only one episode. I wonder if they had an obligation to come up with a different technobabble explanation for why this week's redshirt got vaporized each time?
3:52 PM
@ACuriousMind or oneboxing every video
I'm tired of clicking on links when on mobile and some YT video plays
@ACuriousMind I imagine it would make the editorial meetings quite amusing. Sitting round a table drinking and planning how to vapourise people. It sounds a fun pastime to me :-)
@JohnRennie It's certainly better than being the poor guy who gets vaporized. "I got you a role on Star Trek!" - "Great, what do I portray?" - "You get vaporized in the opening scene."
They literally worked on vaporizing people at Los Alamos.
@skullpatrol Your point being?
@0celóñe7 Hover over links if it bothers you (at least on my phone I can determine the target of a link by long-pressing it instead of a short tap).
Reality can be stranger than science fiction sometimes.
4:01 PM
@skullpatrol not really. Atomic bombs don't vapourise much - just their immediate vicinity. Most of the destruction is due to a regular shock wave. A large shock wave!
@ACuriousMind I don't think that trick works for all phones. Are you using an iphone?
@Blue No, Android
May not be a feature of the OS but of me using Firefox, though
On my S7 it doesn't work (Chrome)
@ACuriousMind Ah, probably
You cannot open a context menu for a link where you could see its target and choose whether to e.g. copy it or open it in a new tab instead of the current tab?
4:04 PM
@Blue as I recall Chrome gives you an open in new tab option but doesn't actually tell you what the link is.
The test-blast melted a football field worth of dessert sand into glass.
@JohnRennie Yes. That it does!
Q: Closing Deleted Duplicates

JMacWhen looking at this question you can see discussion about the closure of this question. Specifically, it quickly got custom flagged as "Duplicate of deleted question by the same user." In terms of actual site performance, this question is mostly semantics; but I am still curious on the procedu...

@skullpatrol melt \ne vapourise
@DawoodibnKareem The social/legal mechanism that enforces the distinction between 'real degrees' and worthless pieces of fancy paper is that governments and employers care about accreditation of schools.
4:06 PM
sand \ne human beings
@JohnRennie One more reason to use Firefox! :P
The only real authority in reality is truth and extremely elaborated falsehood. That is to say, authority is any laws that will kill us if we disobey them
@ACuriousMind browser wars!! :-) Fight, fight!!
It is sometimes a criminal act or a civil fraud to present an un-accredited degree as equivalent to an accredited one for the purposes of obtaining employment, and it is almost always grounds for termination if nothing else.
In other words, the only real authority is natural selection (because we cannot speak if we are dead)
4:07 PM
Big fight on Saturday night!
@Secret that doesn't make any sense. You cannot "disobey" natural selection, it's a principle that operates on populations, not individuals.
Likewise, you cannot "disobey" the truth. Or, if you count lying as disobeying it, then you are evidently wrong because there's a whole lot of non-dead liars around.
Well, in history some tried to defy being selected in some rough sense (e.g. all those search for eternal youth, consuming panacea that is otherwise made of toxic ingridients that don't work etc.), and they are all dead

> then you are evidently wrong because there's a whole lot of non-dead liars around.
This is the reason why I cannot just say truth and must forced to include the concept falsehood in that sentence
Anyway, a more coherent version is basically the answer here:
Q: How are beliefs restricted by an objective reality?

SecretConsider the following belief A human can survive if they don't drink water for 1000 days We knew from biology that this is practically improbable as there are very few people who can survive for 18 days without water (Andreas Mihavecz in 1979). However, there are also beliefs that are unr...

There are truth and falsehoods that kill us if we deny them, and there are those that don't
Karma catches-up to liars.
So in some possibly abusing of terminology sense, those that kill us are like an absolute authority that we cannot disobey else we are dead
Not sure if that metaphor(?) is clear
@skullpatrol lol.
4:14 PM
That's so naive.
That's just the way I am, pal.
If there exists any truth that can be challenged, then we would have expected magic dominates our society and not science, but science is shown to work all the time, which means any well established truth cannot be denied (even though we can never speak of it directly, but only modelled them approximately by better and better physics models, if you get what I mean)
@ACuriousMind It's only a principle as long as you believe it's a principle, though? To someone who is not aware of it, it's not a principle :P
@Secret No, it's entirely unclear to me. Sure, there are some beliefs that, if you act upon them, lead to your death. I have no idea what that has to do with "authority" or "obeying", though.
If you act on a belief, isn't that the same as obeying it in some generalised sense, and thus if you choose not to act on it, it is the same as disobeying it.

Unless, the notion of authority only make sense for individuals or groups, not concepts or natural laws
4:17 PM
@skullpatrol You need to look at examples of people who keep suffering even when they are completely innocent. And on the other hand you have bloody criminals never getting caught. Karma is a myth.
Death and authority always win.
@Secret Of course well-established truths can be denied. Cf. e.g. young-earth creationism, many conspiracy theories, people claiming GR is wrong, etc.
@Blue Karma is a lie, which is meant to keep people in line
Those are the cases where denying does not lead to death. But for things like "falling into lava will cook you", should you deny that, it is certain death
@Secret The latter. I have no idea what you mean by "authority" or "obeying". To "obey" means to follow an instruction, such as a law about behaviour passes by some authority. "True" statements are not instructions (or prohibitions), so you can't obey them.
4:19 PM
@PrathyushPoduval Exactly
It is unclear which statements are true, though.
@Secret No, I can perfectly well hold the belief "Falling into lava is not deadly" and then spend my entire life without jumping into lava (if only because I never actually get close to lava).
Or you might believe that falling into lava is not deadly but is very painful
@BalarkaSen I mean 'is' statements as opposed to 'ought' statements, if you want to be nitpicky.
Ok, fair
4:21 PM
Life is short.
@ACuriousMind Right not acting opposite to the belief will not kill you, but if denying and acting on what you deny it will most certainly kill you even if you deny it
@ACuriousMind Right, you have a point, in that case the notion of authority really don't make sense if the thing is a natural law or a proposition
@Secret Yes, but someone believing that lava is deadly and then stepping into it by accident will also die. It's not the belief that kills you, it's the action.
Sure, some beliefs can lead to deadly actions with a higher frequency.
But I don't think you have to make a giant metaphysical notion out of that.
Right, in that case it is not really belief, but the action itself, which if some objective reality exists, means it is tied to some natural laws. That inability to not suffer the consequence of the action when performing it is one reason they felt analogous to an authority who when disobeyed will surely kill the offenders
Or put it simply, nobody has the freedom to choose not to suffer from performing an action that will kill them, so to speak
I think this alone is probably why science is such a good description of reality as we observed so far as a society
Hello folks.
Sorry hbarians, these weeks have been crazy and I could not add much to the h bar.
@AccidentalFourierTransform I need to ask you a question about the UAM.
@JaimeGallego What's UAM?
4:32 PM
The Autonomous University of Madrid (Spanish: Universidad Autónoma de Madrid; informally La Autónoma), commonly known by the Spanish acronym UAM, is a Spanish public university established in 1968. It is located in northern Madrid; its main campus, Cantoblanco, is located near the cities of Alcobendas, San Sebastián de los Reyes and Tres Cantos. Throughout its history, UAM has been one of Spain's most prominent higher education institutions, being ranked first amongst Spanish universities by the El Mundo University Supplement (known as "Las 50 Carreras"), by The Times Higher Education Supplement...
An university in Madrid
I'm founding this cryptography club
@JaimeGallego Wow. Have you already joined?
Haven't heard from you for long
And for that I will have to put up some posters in libraries and stuff
4:34 PM
Did you drop your plan of going to the States?
Yeah, I already registered madridcrypto.club
And other media
@JaimeGallego "No" to which question?
I will enslave my teachers to write rec letters
@JaimeGallego Heh, as transfer student?
@Blue The US thing
@Blue Freshman! Still in HS
4:37 PM
Oh. I see. Good luck for next year
Thanks. And how are you doing there in India?
@JaimeGallego Already in university :) (Electronics engineering)
Session started a few weeks back
@Blue Nice. Many of my classmates are also going that path. We're an engineer bunch.
@BernardoMeurer New phone?
4:43 PM
@JaimeGallego He's also not been in here much recently, having moved to SB and stuff
@JaimeGallego Same here. Most of my friends either went for engineering or medical. I wanted to go for pure physics but was forced into engineering. :P
I was amaza @JaimeGallego cause he's an engineering student
@SierraSorongon Physics actually, but it's pretty much the same thing.
@JaimeGallego ::ahem::
4:45 PM
lol ^ :P
: ahem :
I refuse to be called an engineer and the engineers I know wouldn't want to be confused with me, either :P
@ACuriousMind Zill has Engineering on its title and undergrads love it!
@JaimeGallego No idea what Zill is
Zill conveys a sense of zeal to them, then, I guess.
High fives? Come on? Nobody?
@JaimeGallego That sounds like barbecue for vegetarians.
@ACuriousMind you're damn right
you're a mathematician
@JaimeGallego how is it you manage to look completely different in each profile picture
@0celóñe7 I'm Bourbaki
quick, what is the automorphism group of $\mathrm{Diff}(S^7)$ with the standard structure
Bourbaki would know
@Loong Your Griffith is a hamster and Feynman smelled of elderberries.
5:00 PM
@JaimeGallego hello there
@ACuriousMind Engineering has become a very vague term nowadays....with fields like Quantum Engineering, Engineering Physics, etc coming up. If you mean EEs/MEs/Civil engineers (the core branches), then yes. They can't be called physicists.
what is engineering physics even supposed to be
@0celóñe7 Applied Physics
that term has been around for 30 years btw
my dad got his MS in that...he's no physicist
@Blue how is applied physics different from engineering
@0celóñe7 It's a hodge-podge degree tbh. It's a mixture of EE+ME+CS+Physics
5:02 PM
no, his was very focused
@AccidentalFourierTransform Could I pin posters at this time of year on the Facultad de Ciencias board?
On the UAM
I would say yes
but perhaps its best for you to wait a week or so
@ACuriousMind halp
@0celóñe7 I was speaking of the "Engineering Physics" degree in our country. Maybe in the US it has a different meaning
Im not sure August is the best month to do anything
1) they may be closed and 2) they may remove everything from the board for the new course
5:04 PM
@ACuriousMind "In fact these matrices define a representation of degree 2 over any ring $R$, because although the rep was initially constructed over $\Bbb R$ the matrices have integer entries, and these may be interpreted in every ring"
@ACuriousMind By "interpreted" do they mean $\Bbb Z\ni k\mapsto k\cdot 1\in R$?
@PrathyushPoduval of course it does not! Mis-translating a part of a scientific text may mislead the reader and may make the problem unsolvable.
@0celóñe7 Probably, yes
@0celóñe7 What does he do nowadays?
5:07 PM
@Blue retired now
no one knew what he did
shady government work
@0celóñe7 Maybe he was the Bond of US ;)
@0celóñe7 How're you so sure? You just said no one knew what he did :P
@ACuriousMind can u look on page 3 of the rep theory book
best article ever
5:18 PM
is that like a spanish email?
insert "only Mathematica users will get this" meme here
@EmilioPisanty will probably get it
Krasnikov used to have a .su email on his old articles
(of the soviet union)
@ACuriousMind I take your silence as a yes
he says that every ring $R$ allows for a rep of $S_3$, ok, but he says "copy"
Does he mean faithful?
5:22 PM
I find that pretty hard to believe for $\Bbb Z_2$
considering the matrices have three distinct entries
@0celóñe7 Yes. If you look closely, you'll see that all these matrices are distinct even for $\mathbb{Z}_2$ where $1=-1$.
@ACuriousMind Hmm
How would one prove that it is faithful for any ring?
@0celóñe7 The image of $\mathbb{Z}$ will always either be $\mathbb{Z}$ or one of the $\mathbb{Z}_n$. That it is distinct for $\mathbb{Z}$ and $n\neq 2$ follows from $1\neq -1$, and we just checked the case $n=2$ explicitly.
@0celóñe7 Of the assertion about the image of $\mathbb{Z}$?
5:30 PM
Or is it Trivial
The image is clearly cyclic, i.e. has one generator. You determine its order $n$ to get an explicit isomorphism to either $\mathbb{Z}$ or $\mathbb{Z}_n$ by mapping that generator to 1.
Of course
that's why I said Trivial
Why do you capitalize the "t"?
for the same reason I captialize the Evidence
Trival Evidence
evidently trival
to Einstein
5:44 PM
@Qmechanic Are you sure making this a res. rec. question instead of editing out the request for papers and advising OP that a request for references is typically always implied was the right choice?
Because this way, it would not be a proper answer if someone actually answered the question instead of recommending a reference, and OP seems more interested in getting their specific question answered than in obtaining general references.
6:02 PM
@Черенки *random algebra and linear algebra
Abbot “Understanding Analysis”
Munkres “Topology”
Jost “Postmodern Analysis” (0-11)
Halmos “Measure Theory”
DiBenedetto “Real Analysis”
Lee “Topological Manifolds”
Lee “Smooth Manifolds” (1-16)
Wald "General Relativity"
O’Neill “Semi-Riemannian Geometry”
start there
Halmos and DiBenedetto are probably too much for this
but you'd need them for QM so it's a good idea regardless
@BalarkaSen Are you free tomorrow morning? Or do you have school?
Anyone know the eqation for the inside of a sphere of radius r?
@Blue Not going school tomorrow.
@BalarkaSen why
6:11 PM
are you skipping school
@ACuriousMind : No, you are right, I'm cutting corners. You are welcome to edit out the res. rec. subquestion, if you think it makes it a better post.
calculating gravity equation
hypothetical body
@BalarkaSen Oh. Then can we continue with LA in the morning (before 8 am) ? When do you wake up?
I wake up at awkward times. Certainly never in the morning.
6:13 PM
@BalarkaSen lol. Okay. Can't risk it then. Can we do LA now, then? :P
We can continue at a better date if you have work today
@BalarkaSen Nah. It's okay. I was just feeling a bit sleepy. But, LA is more important than my pesky sleep.
I disagree but ok
@Qmechanic Okay, I've done so and left a comment for OP
6:55 PM
@0celóñe7 Skipping school is the best thing someone can do.
Schools don't do anything
@Sid people who skip school do drugs and rob stores
good people don't skip school
High school was one of the worst time I had.
Learnt nothing great.
maybe you should have eaten more fish
@ACuriousMind I have a professor who signs all of his emails with his first name only, but everyone calls him by his last name
should I just call him by his first name and see what happens?
7:00 PM
@Sid In that case you're attending a sorry excuse for a school :P
@0celóñe7 yes
@ACuriousMind is this sarcasm
should I ask first?
@0celóñe7 No. If someone signs with their first name I'd have no qualms about calling them by it.
Of course you can ask first if you feel uncomfortable
@ACuriousMind I really want to call elven lord by his first name because his last is simply impossible
@ACuriousMind it was apparently the "best school of the state"
but he always signs with both names
@Sid sorry excuse for a state...
Well, you did say "nothing great," not "nothing at all"
7:03 PM
@0celo7 I sort of agree to that. :P
@ACuriousMind do you ever have random mini math crises
@Sid And that's the point where I question both the criterion of "best" used there and what you meant by "Schools don't do anything". Do you mean you didn't learn anything or that you didn't particularly care for what you learnt?
@0celo7 Possibly, but I can't distinguish them from the overarching existential crisis that is my life :P
I do spite a lot of people who are better at math than me.
so, Mike, ???
7:07 PM
Qiaochu is incredible
yeah that guy is fantastic
no matter what I look up on MO, he has an answer
I don't actually spite Mike because he's a good friend now.
I used to spite people, then I started liking math no one here cares about
@BalarkaSen want some sets of finite perimeter?
7:09 PM
oh I actually accepted that as a viable solution, that's what I started studying foliations
@0celo7 No but I can give you some pseudo-Anosov foliations
@BalarkaSen what are those?
@BalarkaSen I used to. But then I felt it is more productive to spend time with them than to spite them :P (Perhaps it is possible to do both at the same time...who knows XD)
I spite my advisor because he gives me literally dozens of books and I can't/don't read them
not sure what he expects me to do
@0celo7 loooool
@Blue I dunno, I don't feel much motivation for being productive. The notion of productiveness seems pretty vacuous to me.
@ACuriousMind well, that is a tough one to answer. Basically, I was beyond thebpoint of caring what grades I received. I mean, it is not like I didn't learn anything, it was more because didn't really learn it in an "interactive (?)" Way
7:18 PM
@Sid I'm not sure I know what you mean by "interactive"
@BalarkaSen Productiveness provides satisfaction at the end of the day for sure
I strongly believe that if someone is the smartest person in the room, they are in the wrong room. :) So much to learn from everybody!
@ACuriousMind neither do i. I have the notion that people are taught in a much better way elsewhere
@ACuriousMind see above: that's a spicy meme
A meme has to be a relevant reference + timing
Note that it's spicy, not dank. Those are distinct.
@Sid It's possible. The tiny glimpses I've gotten of the Indian education system through various conversations here would support that.
7:30 PM
@BalarkaSen I concur it is buzzwordy, but productiveness isn't vacuous at all. Doing stuff that contributes to society is a noble goal and can be done in nonvague ways.
@0celo7 I have literally no idea what that video is about
@Blue Indeed!
@Blue Ugh. Sometimes the smart person might be in the room just to have a pleasant conversation, not to learn something. :P
@ACuriousMind :/
What do you do on the internet?
Besides dodge GOT spoilers
@JaimeGallego I do not feel nobility in contributing to the society. I do not feel like I should spend my life trying to do things that contributes to the society.
Whatever impression that might give of me, that's true.
I do not justify my existence as part of a contributing agent of a society, or more generally, the human civilization.
7:35 PM
@ACuriousMind True that. That would probably fall under the recreation/relaxation category. But again, too much of recreation/relaxation might be harmful. My point being, if you want to maximize your knowledge you should hang around with smarter guys. (Hope I'm being clear. Don't take that sentence too literally :P)
That said. I gotta go to sleep.
Sleeping too early?
@BalarkaSen That's fair and a valid point. My view is that, although we are all eventually going to die, why not do this psychological trick that gives us some sense of happiness? If there is no difference, I prefer going for that path.
And if that lengthens our existence, I'm all for it.
@JaimeGallego Ok, so now you're talking about a sense of happiness or satisfaction like Blue said. That's a much better and understandable goal for me than to strive for the progress of human race. But I still don't find comfort in that notion, knowing that any notion of happiness is deeply rooted in base pleasures of human creatures.
7:39 PM
Base pleasures of human creatures are awesome.
Right out of the underground, aren't you?
existential rot has taken place clearly
@BalarkaSen Just saying I see nothing wrong with happiness.
Well, what do you mean by "wrong"? That's a subjective idea in the first place. I don't see anything wrong with happiness or any of the extreme forms of pleasure seeking either.
@BalarkaSen Well, what do you mean by "comfort"?
Oh man, this is much better.
How come I have never seen this

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